Where a prosecutor commits misconduct in order to secure a conviction, retrial is not barred even if the conviction is later vacated. The defendant sought a writ of prohibition against retrial on murder charges after a federal court issued a writ of habeas corpus vacating his original conviction due to the prosecutor’s having withheld exculpatory evidence. Although the California Constitution’s broad double jeopardy protections do bar retrial where the prosecution deliberately commits misconduct in order to cause a mistrial in a case in which an acquittal appears to be imminent, case law does not extend this protection to a case in which the prosecution intentionally procures a conviction through misconduct.